Almost one million new cases of cancer occurs a year in the United States, and the incidence increases markedly with age for most cancers. Following cardiovascular disease, cancer is the most frequent reason for hospital admissions for the elderly, and cancer incidence rates are continuing to rise for the older population. Important questions remain regarding access to, outcomes of, and costs for, the care of older patients with cancer. For example, there is evidence of variations in the use of breast-conserving surgery for breast cancer; controversy over the use of adjuvant chemotherapy for breast and colorectal cancers; debate over the appropriate procedures for prostate cancer; and, indications that non-illness characteristics may play a role in the choice of therapy for breast and lung cancers. To improve the effectiveness of care for patients with cancer, practice differences in the treatment of cancer patients are important to describe so that policy-makers can focus efforts to reduce variations. In addition to age, a number of patient factors such as race, geographic location, socioeconomic status and comorbidity from other chronic illnesses are also important considerations that may lead to practice variations. The introduction of newer technologies and the continuing care of more older patients with cancer has led to an increasing proportion of expenditures for cancer in the Medicare program. The care of cancer patients in the last year of life accounts for eight percent of all Medicare expenses. Nonetheless, the costs of treatment and surveillance for cancer patients have not been adequately quantified because of a dearth of information on the costs of different stages of disease, lack of cost information on a cohort of cases, and an inability to control for co-morbid conditions. This study proposes to: 1) use tumor registry data from the Virginia Tumor Registry, together with Medicare claims data and state personal income tax data to evaluate choice of initial treatment for cancer in an elderly cohort 2) evaluate the influence of initial choice of therapy, patient characteristics, tumor characteristics, comorbidity and geographic location on outcomes and, 3) estimate the costs associated with the care of cancer patients according to patient characteristics, tumor stage and type of cancer, as well as comorbid illness.